ARM: PCI: Remove the IXP PCI driver

The driver is no longer used, remove it.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Albert Aribaud <albert.u.boot@aribaud.net>
Cc: Michael Schwingen <michael@schwingen.org>
Cc: Tom Rini <trini@ti.com>

doc/driver-model/UDM-pci.txt

@@ -125,10 +125,6 @@ III) Analysis of in-tree drivers
       Shared driver for indirect PCI bridges, several CONFIG macros - will
       require significant cleanup.
 
-    pci_ixp.c
-    ---------
-      Standard driver, specifies all read/write functions separately.
-
     pci_sh4.c
     ---------
       Shared init function for SH4 drivers, uses dword for read/write ops.